Aw, come on. No Canberra hate from you people? That’s positively UNAUSTRALIAN!
I admire the methodicality of Ben Reimers in his answer. In fact, do look at it: Ben Reimers’ answer to Is Canberra the worst city in Australia?
The emotive definition of a good city to live in, that OP is presumably after, is not intrinsically about access to a beach. Or at least, I don’t think it is, being not much of a beach-goer. (That’s un-Australian too.) But it is critical mass of population, to sustain a vibrant cultural, entertainment, and gastronomical life; good amenities; and nice landscape.
To some, it needs to be “a good place to raise a family”. Mila Karmacharya has said it, just as many say it about Perth.
That criterion is not necessarily antithetical to “critical mass of population, to sustain a vibrant cultural, entertainment, and gastronomical life”. But, well, if it is, that decides me on it. And decides everyone whole who lives in Sydney or Melbourne on it too.
The way out is to say that Canberra is too small to be a city to begin with. It certainly feels that way. Especially if you’re trying to get a cab in the afternoon, to get to the airport to escape Canberra.
It is true that the restaurant scene has improved radically in the last decade. There are even honest-to-God bars in Canberra now. (I hesitate to say pubs.) And I did see a homeless mission wondering about the CBD at night; so it’s not as Stepford as I’d thought it is.
But of the capitals of states and territories, it is certainly the sleepiest. And that weighs heavily on anyone who lives in Sydney or Melbourne.